In modern milking systems, a milker unit is provided for each stall where a cow is to be milked, each milker unit comprising a milk claw and a set of teat cups through which milk is delivered to the claw under vacuum from the cows teats. From the claws of the respective units, the milk flows under vacuum to a common destination such as a pipe line leading to a cooling and storage tank.
It is important to clean the milking system promptly after each use. Otherwise, consistent production of high quality milk with low bacteria counts cannot be assured.
In order to eliminate the necessity of disconnecting the milker units from their common vacuum source and carrying them from the stalls to a cleaning site, various so-called clean-in-place (CIP) systems have been devised. These systems, of course, require means for supplying a washing solution to the teat cups of the milker units at the stalls. To function properly, each unit washer also requires a drain and a valve to shut off vacuum to the unit washer during milking.
These requirements were met by an arrangement disclosed in part in Heitman U.S. Pat. No. 3,834,407 granted Sept. 10, 1974. In that arrangement, each milking stall is provided with a manifold which is connected through a tube to the usual vacuum/wash pipe line of the milking system to receive the washing solution. Each manifold has four nipples onto which the teat cups are pushed and held to supply the solution to the milker unit, the solution then being drawn from the milk claw under vacuum. The drain is located at the bottom of the manifold, and a manually operated pinch valve is provided on the solution supply tube to shut off the vacuum to the manifold during milking. A cover is held in a raised position during cleaning and can be lowered to cover the manifold nipples during milking.
One problem with this prior arrangement is that only the inside of the teat cup liners is cleaned. That is, since the washing solution is supplied through the nipple which is pushed inside the liner, the solution cannot reach any other surface. Another problem is deformation of the liner's mouth by the nipple which at least partly supports the teat cups. Moreover, the cover requires separate manual operations to move it between its raised and covering positions.
The above-noted prior arrangement has been improved by use of so-called jetter-cups in lieu of the manifold. A jetter-cup is a rubber cup into which the enlarged end portion of a teat cup is received rather than this end portion receiving a manifold nipple. This avoids deformation of the liner's mouth piece and allows circulation of cleaning solution around the outside of the liner for complete cleaning of its head. Moreover, the jetter-cups during milking can be hung out of the way on a storage unit which can also be used as a milker unit hanger, eliminating the need for another bracket.
However, the typical jetter-cup storage unit is difficult to use and easily damaged. Storage is accomplished by sliding each jetter-cup under a protective hood between a pair of wires. To adequately insure cleanliness, the fit between the hood and the wires must be quite tight, which causes binding when the jetter-cups are slid into place. This often leads to improper storing of the jetter-cups, thus defeating the purpose of the protective hood. Further, jetter-cup systems usually include a drain, distributor, hanger and vacuum shut-off valve in addition to the jettercups, these parts being interconnected by several milk tubes for proper operation. Also, these prior systems still require the operator to remember to open and close the vacuum shut-off valve of each unit before and after each milking.
The principal object of the present invention is to provide a milker unit washing device which avoids the abovenoted problems with prior washing devices.